Late Winter or Early Spring is Best Time to Prune Trees

The Colorado State Forest Service reminds residents that late winter or early spring is the best time to prune most trees as Spring is approaching.

Trees are still dormant during this time of year, and wound closure will occur sooner if pruning occurs just before new growth emerges. Pruning should wait until the leaves are fully extended once leaf and flower buds start to expand.

“Pruning trees during the late dormant season maximizes growth and allows the tree owner to spot problem areas and build a strong structure for the long term,” said Kamie Long, supervisory forester for the Colorado State Forest Service (CSFS). “Long noted that although some elm, maple, birch, and walnut trees may visibly exude sap if pruned in the late winter or early spring, this should not harm the tree,” Kamie said.

Tree pruning tips the CSFS offers are as follows:

• Know what you want to accomplish before you start pruning. Don’t remove any living branches without a good reason or specific objectives in mind, such as removing crossing/rubbing branches, lifting for height clearance, creating good structure, etc.
• Remove any torn, dead, or broken branches (this can be done any time of the year).
• For shade trees, develop or maintain one dominant vertical top stem or leader, and don’t cut off trees’ tops. If the tree’s height is a concern, there are other methods to reduce tree height or consider replacing the tree with a shorter species.
• Create adequate spacing of the main branches along the trunk, and prevent branches below the permanent canopy from growing upright or getting too large.
• Always prune just outside the branch collar, the point where one branch attaches to a larger one (or the trunk), often discerned by raised or wrinkled bark.
• Limit pruning of newly planted trees to remove dead, damaged, or crossing limbs, or those interfering with the main stem, until the tree becomes established in the landscape.
• Avoid removing too many of a tree’s branches in any one year, which puts undue stress on the tree. The amount depends on how much growth the tree has produced in the previous years.
• Consider recycling pruned limbs by having them ground into mulch.

If a job requires running a chainsaw overhead or removing large branches or entire trees, Kamie said it is best to contact an insured ISA Certified Arborist.

“Pruning can be done in the summer to avoid sap flow, especially with maple trees,” said Kamie.

For more information regarding a list of the professionals listed above, visit: www.isa-arbor.com or learn more about urban tree care, visit csfs.colostate.edu.